Shelter bed

ABSTRACT

A shelter bed comprising: a mattress on which at least one user can lie down; a frame on which the mattress is set, and which comprises legs supporting the entire shelter bed on a floor and a buoyancy device generating buoyancy holding the entire shelter bed on a water surface; and a protective shell for protecting the user, the protective shell being movable between a first position in which the protective shell covers the user lying on the mattress and a second position in which access to the mattress is released to the user.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a shelter bed, and in particular, to ashelter bed for protecting a user's body from falling objects in anevent of disasters, and for allowing a user to urgently evacuate in anevent of water-related disasters such as house flooding.

DESCRIPTION OF RELATED ART

Japanese Patent Application Laid-open Publication No. 8-294430 disclosesan earthquake disaster shelter bed allowing a person to shelter oneselfinside a bed frame thereof having loading capacity of 2 tons. A drawingcontainer is provided in the shelter for containing emergency survivalsupplies such as water, foods and a flashlight.

Japanese Patent Application Laid-open Publication No. 2002-85197discloses a bed for rescue and first-aid. The bed includes a mattressformed of a resin foam material and a roof wall member to be attached tothe mattress. The roof wall member is normally folded, and, whenunfolded, forms a shape surrounding the mattress, which has a pair ofroof top portions and a pair of substantially triangular gable sideportions respectively supporting both ends of the roof top portions. Themattress provides buoyancy large enough to float at least one user on awater surface. When houses are flooded in an event of water-relateddisasters, the mattress allows a sick or physically disabled individualto float on the water surface. In a prolonged life as evacuees, user'sprivacy can be secured by attaching the roof wall member to themattress.

SUMMARY OF THE INVENTION

As for the former of the above-described beds, a user has to move to ashelter provided inside the bed frame so as to protect his/her body fromfalling objects such as rubble of houses in an event of earthquakes andthe like. This movement is difficult for persons incapable ofimmediately moving their bodies, such as a physically disabled and sickindividual.

As for the latter of the above-described beds, there is a problem that auser cannot protect his/her body from rubble falling onto the bed in theevent of disasters such as earthquakes. Moreover, since the mattress hasa flat shape, the mattress is unstable when floating on the watersurface and causes large drag when moving on the water surface, whichmakes it difficult for a rescue worker to tow the mattress with aphysically disabled or sick individual thereon while keeping his/herbody on a water surface in the event of water-related disasters.

The present invention was made in the light of these problems. An objectof the present invention is to provide a shelter bed which quicklyprotects the user lying on the shelter bed from falling objects in anevent of earthquakes and the like, and achieves sufficient and stablebuoyancy to have the user floated on a water surface and to make rescuework easier in the event of water-related disasters.

An aspect of the present invention is a shelter bed comprising: amattress on which at least one user can lie down; a frame on which themattress is set, and which comprises legs supporting the entire shelterbed on a floor and a buoyancy device generating buoyancy holding theentire shelter bed on a water surface; and a protective shell forprotecting the user, the protective shell being movable between a firstposition in which the protective shell covers the user lying on themattress and a second position in which access to the mattress isreleased to the user.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the accompanyingdrawings wherein:

FIG. 1A is a perspective view showing a shelter bed according to a firstembodiment of the present invention, the shelter bed having a protectiveshell being housed therein;

FIG. 1B is a perspective view of the shelter bed of FIG. 1A, which showsa state where the protective shell is moved to cover a person lying onthe shelter bed;

FIG. 2 is a front view of the shelter bed of FIG. 1A in which a leg onthe left side of the bed is omitted;

FIG. 3 is a cross-sectional view of the shelter bed of FIG. 1A, which istaken along the line III-III of FIG. 2;

FIG. 4 is a cross-sectional view of the shelter bed of FIG. 1A, which istaken along the line IV-IV line of FIG. 2;

FIG. 5 is a perspective view showing a shelter bed according to a secondembodiment of the present invention;

FIG. 6 is a side view of the shelter bed of FIG. 5, which is viewed fromthe head side;

FIG. 7 is a perspective view showing a shelter bed according to a thirdembodiment of the present invention;

FIG. 8 is a side view of the shelter bed of FIG. 7, which is viewed fromthe head side, and in which a headboard is omitted;

FIG. 9 is a perspective view showing a shelter bed according to a fourthembodiment of the present invention; and

FIG. 10 is a perspective view of the shelter bed of FIG. 9, which showsa state where the protective shell is moved to cover a person lying onthe shelter bed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be explained below withreference to the drawings, wherein like members are designated by likereference characters.

As shown in FIGS. 1 to 4, a shelter bed 1 according to a firstembodiment of the present invention is provided with a rectangularmattress 5 having such a size that at least one user can lie down on themattress 5, and a bed frame 3 onto which the mattress 5 is set.

The bed frame 3 includes a pair of legs 7 which supports the entireshelter bed 1 on the floor, and which extend in the longitudinaldirection of the shelter bed 1 (from the head side to the hoot side)along right and left side edges of the shelter bed 1 (both ends in thewidth direction of the bed), and a buoyancy device 9 which is providedbetween the two legs 7 below the mattress 5, and which generatesbuoyancy to hold the entire shelter bed 1 (including the user laying onthe mattress 5) on a water surface.

The leg 7 has a substantially rectangular shape in a plan view and incross-section perpendicular to the longitudinal direction of the bed.The buoyancy device 9 as a whole has a ship shape, and has a shape of aship's bottom showing a substantially V-shape in the cross-sectionperpendicular to the longitudinal direction of the bed. That is, in thecross-section perpendicular to the longitudinal direction of the bed,the legs 7 and the buoyancy device 9 together form a substantially Mshape.

Lower end portions 7 a of the respective legs 7 are submerged in waterwhen the shelter bed 1 floats on the water surface. As will be describedlater, protective shell housing portions 15 are provided inside therespective legs 7. Thus, the legs also form a part of the buoyancydevice 9 to generate buoyancy when the shelter bed 1 floats on the watersurface. The buoyancy generated by these legs 7 generates a moment tosuppress the rolling movement around the axis of the longitudinaldirection of the shelter bed 1, so that the shelter bed becomes stableon the water surface.

The buoyancy device 9 is formed of, for example, a resin foam materialsuch as styrofoam, an air bag (a buoyancy bag), or the like.

The bed frame 3 is provided with a protective shell 11 for protecting auser. The protective shell 11 is provided above the mattress 5 in a waythat the protective shell 11 is movable between a closed position (afirst position) in which the protective shell 11 covers a user lying onthe mattress 5 and an open position (a second position) in which accessto the mattress 5 is released to the user.

In the first embodiment, the protective shell 11 is formed of a pair offlat plate members 13 forming a gable roof in the closed position. Theseflat plate members 13 are formed of, for example, a resin plate materialsuch as a reinforced plastic or a metal plate material such as stainlessmaterial.

The protective shell housing portions 15 for housing the respective flatplate members 13 are provided inside the respective legs 7. In the upperportions of the respective protective shell housing portions 15, openingportions 17 into which the respective flat plate portions 13 areinserted are formed. The opening portions 17 extend in the longitudinaldirection of the shelter bed 1 along right and left end edges of theshelter bed 1.

A flat headboard 19 and a flat footboard 21 are respectively provided tothe head and foot sides of the shelter bed 1. Mountain-shaped guidegrooves 23 are respectively provided to the sides of the headboard 19and the footboard 21, the sides facing each other. Each of the guidegrooves 23 guides a corresponding one of the flat plate members 13 whichmoves between the open position in which the flat plate member 13 ishoused inside the corresponding protective shell housing portion 15 andthe closed position in which the gable roof is formed above the mattress5. Moreover, the flat plate members 13 support loads applied from aboveonto each flat plate member 13 in the closed position.

The headboard 19 and the footboard 21 each have space (not shown) insidetheir thicknesses. As shown by the chain double dashed line on the leftside in FIG. 4, a protective shell driving device 25, which drives thecorresponding flat plate member 13, is provided inside each space. Theprotective shell driving device 25 is formed of, for example, aplurality of sprockets 27 fixed to the headboard 19 or to the footboard21; chains 29 intermeshing with the sprockets 27 in an endless annularform; and a rotation driving unit 28 such as a motor which causes thechains 29 to rotate in forward and reverse direction. The plurality ofsprockets 27 at least includes a sprocket 27 a provided near an apexformed by the mountain-shaped guide grooves 23, a sprocket 27 b providedto a vicinity of one of the opening portions 17 of the respectiveprotective shell housing portions 15, and a sprocket 27 c positionedabove a line connecting the sprockets 27 a and 27 b to each other. Inthe first embodiment, a total of four protective shell driving devices25 are respectively provided to right and left sides of the headboard 19and the footboard 21.

To upper end portions 13 a of the side edges on the head and foot sidesof the respective flat plate members 13, a connecting member 13 b isattached with an unillustrated connecting shaft. Each flat plate member13 b is connected to the corresponding chain 29 of each protective shelldriving device 25. Thus, the upper end portions 13 a of the side edgeson the head and foot sides of the respective flat plate members 13 moveamong the sprockets 27 along with the rotation of the chains 29. On theother hand, each of lower end portions 13 c of side edges on the headand foot sides of the corresponding flat plate member 13 moves whilebeing guided by the guide groove 23.

For example, when the chains 29 is rotated forward (clockwise rotationin FIG. 4) by the rotation driving unit 28, each flat plate member 13housed inside the corresponding protective shell housing portion 15 isonce pulled out upward, and then moves toward the apex formed of theguide grooves 23 to stop at a stop position on the upper end of thecorresponding guide groove 23. This operation is shown by the chaindouble dashed line in FIG. 4. At the stop position, the upperend edgesof the respective flat plate members 13 are in contact with each otherover the entire length thereof. Thereby, each flat plate member 13 formsa gable roof above the mattress 5 to cover the user lying on themattress 5 as shown by the chain double dashed line hatching in FIGS. 1Band 4.

When the chains 29 are reversely rotated (anticlockwise rotation in FIG.4) by the rotation driving portion 28, each flat plate member 13performs an operation opposite to that in the case of the forwardrotation, and moves by being guided by the guide grooves 23. Thereby,the flat plate members 13 are respectively stored in the protectiveshell housing portions 15.

It is to be noted that the protective shell driving device 25 shown bythe chain double dashed line on the left side in FIG. 4 represents theabove-described four protective shell driving devices 25 to which otherprotective shell driving devices have a similar configuration. Theabove-described protective shell driving devices 25 shows one example.The configuration thereof is not limited to this and may be anotherconfiguration. For example, it is possible to employ a configuration inwhich the upper end portions 13 a respectively of the side edges on thehead and foot sides of the flat plate members 13 are connected to rodsof motor cylinders or fluid cylinders of which crevices are fixed to theheadboard 19 or to the footboard 21.

In addition, the upper end edges respectively of the flat plate members13 may be configured to be engageable with each other in the closedposition. For example, a plurality of hooks are provided along the totallength of the upper end portion of the flat plate member 13 on the leftside of the shelter bed 1 and a plurality of engaging holes to engagewith the hooks are provided respectively in positions corresponding tothe plurality of hooks in the upper end portion of the flat plate member13 on the right side of the shelter bed 1. In this case, rotation speedor the like of the rotation driving unit 28 of the correspondingprotective shell driving device 25 is adjusted so that the flat platemember 13 on the right side of the shelter bed 1 would stop at a stopposition before the flat plate member 13 on the left side stops.

The bed frame 3 includes, for example, a vibration detecting unit 30 afor detecting vibrations or the like caused by P-waves of earthquakesand a control device 30 b for controlling rotations of the rotationdriving unit 28 of the corresponding protective shell driving device 25on the bases of detected values obtained by the vibration detecting unit30 a. The vibration detecting unit 30 a transmits data on detectedvibrations or detected signals to the control device 30 b in the eventwhere P-wave vibrations or vibrations greater than vibrations set inadvance on a seismic intensity scale occur. The control device 30 btransmits the control signals to the rotation driving unit 28 of thecorresponding protective shell driving device 25 on the bases of thereceived data or the detected signals. The rotation driving unit 28rotates forward on the bases of the received control signals, and causesboth of the flat plate members 13 to move to the closed position. Thus,the system is constituted in which the protective shell 11 isautomatically operated to protect a user lying on the mattress 5 whenthe earthquake occurs. Incidentally, the vibration detecting device 30 aand the control device 30 b may be those which receive warnings from awide-area seismic warning system, and which use the received signals forthe above-described control. In addition, the devices may be thoseprovided with functions to generate a SOS signal of which originatingposition can be identified, and to communicate in case of emergency.

A propulsive device is provided in the rear portion of a buoyancy device9 (on the foot side of the shelter bed). The propulsive device propelsthe shelter bed 1 when the shelter bed 1 floats on the water surfacewith buoyancy generated by the buoyancy device 9. The propulsive deviceincludes a screw 33 projected rearward from the rear surface of thebuoyancy device 9; a rudder 35 which is placed in the rear of the screw33, and which changes a direction of propulsion by changing a directionof slip stream of the screw 33; a motor M of which driving shaft isdirectly connected to the screw 33; and a storage battery 32 forsupplying driving power to the motor M. The motor M and the storagebattery 32 are built in a screw driving chamber 31 provided behind thebuoyancy device 9. Incidentally, the number of revolutions of the motorM is controlled by another control device. An operation control panel 31a is provided in one section on the headboard 19 of the bed frame 3. Theoperation control panel 31 a includes an operation switch and the likefor operating the revolution speed of the screw 33 or of the motor M andthe direction of the rudder 35. Using this control panel 31 a, the userof the shelter bed 1 can operate the revolution speed of the screw 33and the direction of the rudder 35 while lying on the mattress 5.

Operations of the shelter bed 1 of the first embodiment will bedescribed below.

As shown in FIG. 1A, the pair of flat plate members 13 are normallyhoused inside the respective protective shell housing portions 15provided in the legs 7 on the right and left sides of the bed. That is,the protective shell 11 is in the open position, the user can freelyaccess the mattress 5, and the shelter bed 1 is used as a normal bed.

In the event where p-wave vibrations or vibrations greater thanvibrations set in advance on a seismic intensity scale occur, thevibration detecting device 30 a automatically transmits detection datato the control device 30 b so that the control unit 30 b controls therotation driving unit 28 of the corresponding protective shell drivingdevice 25 to cause the rotation driving unit 28 to rotate forward. Afterthat, the two flat plate members 13 move to the closed position to formthe gable roof above the mattress 5. As a result, even persons unable toget up from the bed by themselves, such as the physically disabled orthe sick individuals, can immediately protect their bodies from fallingobjects such as rubble of houses and the like in the event ofearthquakes. Here, as described above, if the top edges of the flatplate members 13 are engaged with each other in the closed position, thetwo flat plate members 13 integrally form an angle section. Hence, theflat plate members 13 support significant weight applied fromthereabove.

Furthermore, in the event of water-related disasters such as flood whichfloods houses, the shelter bed 1 immediately changes itself to a boat.That is, the shelter bed 1 can float on the water surface together withthe user on the mattress 5 by receiving the buoyancy generated by thebuoyancy device 9. This shelter bed 1 as a boat has such a bottomsurface that the legs 7 on the respective right and left sides of thebed, and the buoyancy device 9 show a substantially M-shape in thecross-section perpendicular to the longitudinal direction of the bed.Thereby, the shelter bed 1 is stable with suppressed rolling of the boatfloating on the water surface. The propulsion device provided with thescrew 33 capable of adjusting the number of revolutions and the rudder35 capable of steering the bed is provided behind the buoyancy device 9.The user of the shelter bed 1 operates the operation control panel 31 awhile lying thereon, so that the user can easily escape to a saferplace.

Next, a shelter bed 37 of a second embodiment of the present inventionwill be described. It is to be noted that only configurations differentfrom those of the above-described shelter bed 1 according to the firstembodiment will be described in detail. Components which are the same asthose of the shelter bed 1 of the first embodiment will be denoted bythe same reference numerals, and the detailed description of theirconfigurations and operations will be omitted.

As shown in FIGS. 5 and 6, a shelter bed 37 has a semi-cylindricalprotective shell 39. The protective shell 39 is attached to a side edgeof a bed frame 3 in a way that the protective shell 39 can be opened andclosed. The protective shell 39 is attached, for example, to an upperportion of a leg 7 on the left side of the bed with a hinge portion 41on one side of side edges in the width direction of the bed, forexample, the side edge on the left side of the bed. The protective shell39 is formed of a resin plate material such as a transparent orsemi-transparent reinforced plastic.

Incidentally, this protective shell 39 may be configured to be openedand closed manually. However, the protective shell 39 may be configuredto be opened and closed automatically with a following driving mechanismbeing provided. For example, a part of the protective shell 39 whichrotationally moves around the hinge portion 41 may be connected to amotor cylinder and to a fluid cylinder of which crevice is fixed to thebed frame 3. By driving the cylinders, the protective shell 39 may beautomatically driven to be rotated. The protective shell 39 may beconfigured in a way that a gear mechanism is directly connected to arotating member of the hinge portion 41, and that the gear mechanism isrotationally driven by the motor or the like. Hence, the protectiveshell 39 is automatically driven to be rotated.

The description of an operating timing or the like of these drivingmechanisms is similar to that of the protective shell 11 of the firstembodiment. Accordingly, the description is omitted. The directions ofopening or closing the protective shell 39 are not limited to those inthe present embodiment. For example, the left side of the bed, the footside, or the head side may be opened by respectively providing a hingeportion on the right side of the bed, the head side, or the foot side.

Next, a shelter bed 43 according to a third embodiment of the presentinvention will be described. Configurations different from those of theabove-described shelter bed 1 according to the first embodiment will bedescribed in detail. Components which are the same as those of theshelter bed 1 of the first embodiment will be denoted by the samereference numerals, and the detailed description of their configurationsand operations will be omitted.

As shown in FIGS. 7 and 8, a shelter bed 43 has a semi-cylindricalprotective shell 45. As shown in FIG. 8, a pair of circular-shaped guidegrooves 51 are provided respectively to sides of a headboard 19 and afootboard 21, which face each other, for guiding movement of theprotective shell 45 from an open position to a closed position. Anopening portion 49 is provided in a region which is located in the upperportion of one side of side edges in the bed width direction of a bedframe 3, and which is on the left of a mattress 5. The protective shell45 is inserted into, and is passed through the opening portion 49. Aprotective shell housing portion 47 for housing the protective shell 45inserted from the opening portion 49 is provided below a buoyancy device9 of the shelter bed 43. The protective shell 45 is placed in theprotective shell housing portion 47 in a way that the protective shell45 surrounds the buoyancy device 9 from beneath the buoyancy device 9.

The semi-cylindrical protective shell 45 is fit into the guide groove 51on the side edges on the head and foot sides in a way that theprotective shell 45 can slide. The protective shell 45 is rotatablearound the central axis of the semicylinder thereof. The protectiveshell 45 is formed of a resin plate material such as a transparent orsemi-transparent reinforced plastic.

Inside the end portions on the head and foot sides of the bed frame 3 ofthe shelter bed 43 is provided with a protective shell driving device 50for driving the semi-cylindrical protective shell 45. As shown in FIG.8, the protective shell driving device 50 includes a rack 50 a providedto an outer circumferential surface of the protective shell 45 in bothend portions in the longitudinal direction of the bed; a pinion 50 bintermeshing with the rack 50 a; and a rotation driving device 50 c suchas a motor for rotationally driving the pinion 50 b. When the rotationdriving device 50 c rotationally drives the pinion 50 b, the protectiveshell 45 is driven via the rack 50 a intermeshing with the pinion 50 b.Then, the protective shell 45 passes through the opening portion 49along with the rotation around the central axis of the semi-cylinderthereof, while moving between the open position, that is, the positionwhere the protective shell 45 is housed in the protective shell housingportion 47 and the closed position, that is, the position where theprotective shell 45 is above the mattress 5 to cover the mattress 5.Note that the protective shell driving device 50 is one example. Adevice driving the protective shell 45 is not limited to this, and mayhave another configuration. In addition, the opening and closingdirections of the protective shell 45 are not limited to the presentembodiment, and an opening portion 49 may be provided to the right sideof the bed, and the protective shell 45 may be opened from the left sideof the bed.

Next, a shelter bed 53 according to a fourth embodiment of the presentinvention will be described. Configurations different from those of theabove-described shelter bed 1 according to the first embodiment will bedescribed in detail. Components which are the same as those of theshelter bed of the first embodiment will be denoted by the samereference numerals, and the detailed description of their configurationsand operations will be omitted.

As shown in FIGS. 9 and 10, a shelter bed 53 is provided with aprotective shell 55 formed of a plurality of semi-cylindrical dividedshelter shells 55 a, 55 b, and 55 c, each of which is movable in thelongitudinal direction of the bed.

On the upper surfaces of the side edge portions on the right and left ofthe bed frame 3 of the shelter bed 53, guide grooves 57 extending in thelongitudinal direction of the bed are provided. The divided protectiveshells 55 a, 55 b, and 55 c are fit in the guide grooves 57 respectivelyin both end edges in the width direction of the bed in a way that theprotective shells 55 a, 55 b, and 55 c can slide therein in thelongitudinal direction of the bed. In addition, the divided protectiveshell 55 a on the head side and the divided protective shell 55 b in themiddle are movable along with each other. Meanwhile, flanges or the likecapable of being engaged with each another are provided to the endportion on the foot side of the divided protective shell 55 a on thehead side and the end portion on the head side of the divided protectiveshell 55 b in the middle so that both of the protective shells are notseparated from each other completely (a gap between the protectiveshells is not caused in a plan view). The divided protective shell 55 con the foot side and the divided protective shell 55 b in the middlealso have a similar configuration to that described above so that bothof the protective shells would not be separated from each othercompletely. Each of the divided protective shells 55 a, 55 b, and 55 cis formed of a resin plate material such as a transparent orsemi-transparent reinforced plastic.

Inside the legs 7 of the bed frame 3 of the shelter bed 53 is providedwith a protective shell driving device 60 for driving the protectiveshells 55 a, 55 b, and 55 c. As shown in FIGS. 9 and 10, the protectiveshell driving device 60 includes an endless chain 60 a extending alongthe guide groove 57; a pair of sprockets 60 b around which the endlesschain 60 is wound; a rotation driving device 60 c such as a motor whichrotationally drives one of the sprockets 60 b, and a junction 60 d whichconnects the chain 60 a to the divided protective shell 55 a on the headside, and which is movable to the head side or to the foot side alongthe guide groove 57. When the rotation driving device 60 c rotationallydrives the sprockets in the anticlockwise direction in FIGS. 9 and 10,the divided protective shell 55 a is driven through the chain 60 a woundtherearound and the junction 60 d attached thereto to move to the headside along the guide groove 57. When the divided protective shell 55 aon the head side moves by its width in the longitudinal direction of thebed, the head side of the divided protective shell 55 a and a portion ofthe end portion on the head side of the divided protective shell 55 b inthe middle are engaged with each other, and the divided protective shell55 b in the middle also starts moving together with the dividedprotective shell 55 a on the head side. Thereafter, when the end portionon the head side of the divided protective shell 55 a on the head sideis in contact with the headboard 19, all of the divided protectiveshells 55 a, 55 b, and 55 c cover the mattress 5 entirely without a gap.In a case where the protective shell 55 is moved from such a closedposition to the open position, that is, where the protective shell 55 ismoved to a position where all of the divided protective shells 55 a, 55b, and 55 c are gathered on the foot side of the shelter bed while beingstacked on one another, the reverse of the above-described operations iscarried out.

The protective shell driving device 60 is one example. A device fordriving each divided protective shell 55 is not limited to this, and mayhave another configuration. Although the number of divided protectiveshells is three in the above-described embodiment, it may be four ormore. In addition, in the above-described embodiment, the open positionis defined as a position where the divided protective shells aregathered on the foot side. However, the open position may be defined asa position where the protective shells are gathered on the head side.The shape of each divided protective shell is not limited tosemi-cylindrical, and it may be a polygonal column shape.

The preferred embodiments described herein are illustrative and notrestrictive, and the invention may be practiced or embodied in otherways without departing from the spirit or essential character thereof.For example, the size of the mattress is not limited to a single size,and it may be a double size, king size, queen size or the like. Inaddition, the timing of closing the protective shell may not only be atthe time when the vibration detecting device detects vibrations, butalso be any suitable timing after the user on the shelter bed fallsasleep. The buoyancy device is not limited to a fixed type, and may bean air bag which is contained while being normally folded, and whichautomatically expands in case of emergency.

The scope of the invention being indicated by the claims, andcombinations of all or any of the above-described embodiments, allvariations and modifications which come within the meaning of claims areintended to be embraced herein.

The present disclosure relates to subject matter contained in JapanesePatent Application No. 2006-045734, filed on Feb. 22, 2006, thedisclosure of which is expressly incorporated herein by reference in itsentirety.

1. A shelter bed comprising: a mattress on which at least one user can lie down; a frame on which the mattress is set, and which comprises legs supporting the entire shelter bed on a floor and a buoyancy device generating buoyancy holding the entire shelter bed on a water surface; and a protective shell for protecting the user, the protective shell being movable between a first position in which the protective shell covers the user lying on the mattress and a second position in which access to the mattress is released to the user.
 2. The shelter bed according to claim 1, wherein the legs constitute a part of the buoyancy device.
 3. The shelter bed according to claim 2, wherein the legs extend in a longitudinal direction of the shelter bed along both side edges in a width direction of the shelter bed.
 4. The shelter bed according to claim 3, wherein the legs house the protective shell therein.
 5. The shelter bed according to claim 1, wherein the protective shell is a pair of flat plate members housed in the legs, which form a gable roof in the first position.
 6. The shelter bed according to claim 1, wherein one side edge of the protective shell is hinged to the frame.
 7. The shelter bed according to claim 1, wherein the protective shell has a semi-cylindrical shape, and moves between the first and second positions while rotating about the central axis of the semi-cylindrical shape thereof.
 8. The shelter bed according to claim 1, wherein the protective shell includes a semi-cylindrical shell movable in the longitudinal directions of the shelter bed.
 9. The shelter bed according to claim 1, wherein the buoyancy device is provided with a propulsion device for propelling the shelter bed in an event where the shelter bed floats on the water surface. 